搜索结果: 'methocult media formulations for human hematopoietic cells serum containing'

Despite the high incidence of trophoblast-related diseases,the molecular mechanism of inadequate early trophoblast development is still unclear due to the lack of an appropriate cellular model in vitro. In the present study,we reprogrammed the amniotic cells to be induced pluripotent stem cells (iPSCs) via a non-virus and non-integrated method and subsequently differentiated them into trophoblast-like cells by a modified BMP4 strategy in E6 medium. Compared with the previously studied trophoblast-like cells from ESCs,the iPSCs derived trophoblast-like cells behave similarly in terms of gene expression profiles and biofunctions. Also we confirmed the differentiating tendency from iPSCs to be syncytiotrophoblasts-like cells might be caused by inappropriate differentiating oxygen condition. Additionally,we preliminarily indicated in vitro artificial" differentiation of iPSCs also undergoing a possible trophoblastic stem cell stage as witnessed in vivo. In conclusion we provided an in vitro cellular model to study early trophoblast development for specific individual by using the feasible amnion. View Publication

Induced pluripotent stem cells (iPSCs) have the ability to differentiate in any specialized somatic cell type,which makes them an attractive tool for a wide variety of scientific approaches,including regenerative medicine. However,their pluripotent state and their growth in compact colonies render them difficult to access and,therefore,restrict delivery of specific agents for cell manipulation. Thus,our investigation focus was set on the evaluation of the capability of Layer-by-Layer (LbL) designed microcarriers to serve as a potential drug delivery system to iPSCs,as they offer several appealing advantages. Most notably,these carriers allow for the transport of active agents in a protected environment and for a rather specific delivery through surface modifications. As we could show,charge and mode of LbL carrier application as well as the size of the iPSC colonies determine the interaction with and the uptake rate by iPSCs. None of the examined conditions had an influence on iPSC colony properties such as colony morphology and size or maintenance of pluripotent properties. An overall interaction rate of LbL carriers with iPSCs of up to 20 % was achieved. Those data emphasize the applicability of LbL carriers for stem cell research. Additionally,the potential use of LbL carriers as a promising delivery tool for iPSCs was contrasted to viral particles and liposomes. The identified differences among those delivery tools have substantiated our major conclusion that LbL carrier uptake rate is influenced by characteristic features of the iPSC colonies (most notably colony size) in addition to their surface charges. View Publication

The shortage of human organs and tissues for transplant has led to significant interest in xenotransplantation of pig tissues for human patients. However,transplantation of pig organs results in an acute immune rejection,leading to death of the organ within minutes. The $\$-1,3-galactosyltransferase (GALT) gene has been knocked out in pigs to reduce rejection,yet additional genes need to be modified to ultimately make pig tissue immunocompatible with humans. The development of pig induced pluripotent stem cells (piPSCs) from GALT knockout (GALT-KO) tissue would provide an excellent cell source for complex genetic manipulations (e.g.,gene targeting) that often require highly robust and proliferative cells. In this report,we generated GALT-KO piPSCs by the overexpression of POU5F1,SOX2,NANOG,LIN28,KLF-4,and C-MYC reprogramming genes. piPSCs showed classical stem cell morphology and characteristics,expressing integrated reprogramming genes in addition to the pluripotent markers AP,SSEA1,and SSEA4. GALT-KO piPSCs were highly proliferative and possessed doubling times and telomerase activity similar to human embryonic stem cells. These results demonstrated successful reprogramming of GALT-KO fibroblasts into GALT-KO piPSCs. GALT-KO piPSCs are potentially an excellent immortal cell source for the generation of pigs with complex genetic modifications for xenotransplantation,somatic cell nuclear transfer,or chimera formation. View Publication

Human pluripotent stem cells (hPSCs),including human embryonic stem cells and human-induced pluripotent stem cells,are a renewable cell source for a wide range of applications in regenerative medicine and useful tools for human disease modeling and drug discovery. For these purposes,large numbers of high-quality cells are essential. Recently,we showed that a biological substrate,recombinant E8 fragments of laminin isoforms,sustains long-term self-renewal of hPSCs in defined,xeno-free medium with dissociated single-cell passaging. Here,we describe a modified culture system with similar performance to efficiently expand hPSCs under defined,xeno-free conditions using a non-biological synthetic substrate. View Publication

Fanconi anemia (FA) is an autosomal recessive disorder characterized by progressive bone marrow failure (BMF) during childhood,aside from numerous congenital abnormalities. FA mouse models have been generated; however,they do not fully mimic the hematopoietic phenotype. As there is mounting evidence that the hematopoietic impairment starts already in utero,a human pluripotent stem cell model would constitute a more appropriate system to investigate the mechanisms underlying BMF in FA and its developmental basis. Using zinc finger nuclease (ZFN) technology,we have created a knockout of FANCA in human embryonic stem cells (hESC). We introduced a selection cassette into exon 2 thereby disrupting the FANCA coding sequence and found that whereas mono-allelically targeted cells retain an unaltered proliferation potential,disruption of the second allele causes a severe growth disadvantage. As a result,heterogeneous cultures arise due to the presence of cells still carrying an unaffected FANCA allele,quickly outgrowing the knockout cells. When pure cultures of FANCA knockout hESC are pursued either through selection or single cell cloning,this rapidly results in growth arrest and such cultures cannot be maintained. These data highlight the importance of a functional FA pathway at the pluripotent stem cell stage. ?? 2014. View Publication

Nature Genetics 47,469 (2015). doi:10.1038/ng.3258 View Publication

Expression of genes associated with inflammation was analyzed during differentiation of human pluripotent stem cells (PSCs) to hepatic cells. Messenger RNA transcript profiles of differentiated endoderm (day 5),hepatoblast (day 15) and hepatocyte-like cells (day 21) were obtained by RNA sequencing analysis. When compared to endoderm cells an immature cell type,the hepatic cells (days 15 and 21) had significantly higher expression of acute phase protein genes including complement factors,coagulation factors,serum amyloid A and serpins. Furthermore,hepatic phase of cells expressed proinflammatory cytokines IL18 and IL32 as well as cytokine receptors IL18R1,IL1R1,IL1RAP,IL2RG,IL6R,IL6ST and IL10RB. These cells also produced CCL14,CCL15,and CXCL- 1,2,3,16 and 17 chemokines. Endoderm cells had higher levels of chemokine receptors,CXCR4 and CXCR7,than that of hepatic cells. Sirtuin family of genes involved in aging,inflammation and metabolism were differentially regulated in endoderm and hepatic phase cells. Ligands and receptors of the tumor necrosis factor (TNF) family as well as downstream signaling factors TRAF2,TRAF4,FADD,NFKB1 and NFKBIB were differentially expressed during hepatic differentiation. View Publication

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Stem cells derived from pre-implantation human embryos or from somatic cells by reprogramming are pluripotent and self-renew indefinitely in culture. Pluripotent stem cells are unique in being able to differentiate to any cell type of the human body. Differentiation towards the cardiac lineage has attracted significant attention,initially with a strong focus on regenerative medicine. Although an important research area,the heart has proven challenging to repair by cardiomyocyte replacement. However,the ability to reprogramme adult cells to pluripotent stem cells and genetically manipulate stem cells presented opportunities to develop models of human disease. The availability of human cardiomyocytes from stem cell sources is expected to accelerate the discovery of cardiac drugs and safety pharmacology by offering more clinically relevant human culture models than presently available. Here we review the state-of-the-art using stem cell-derived human cardiomyocytes in drug discovery,drug safety pharmacology,and regenerative medicine. View Publication

Normal stem cells and cancer stem cells (CSCs) share similar properties,in that both have the capacity to self-renew and differentiate into multiple cell types. In both the normal stem cell and cancer stem cell fields,there has been a great need for a universal marker that can effectively identify and isolate these rare populations of cells in order to characterize them and use this information for research and therapeutic purposes. Currently,it would appear that certain isoenzymes of the aldehyde dehydrogenase (ALDH) superfamily may be able to fulfill this role as a marker for both normal and cancer stem cells. ALDH has been identified as an important enzyme in the protection of normal hematopoietic stem cells,and is now also widely used as a marker to identify and isolate various types of normal stem cells and CSCs. In addition,emerging evidence suggests that ALDH1 is not only a marker for stem cells,but may also play important functional roles related to self-protection,differentiation,and expansion. This comprehensive review discusses the role that ALDH plays in normal stem cells and CSCs,with focus on ALDH1 and ALDH3A1. Discrepancies in the functional themes between cell types and future perspectives for therapeutic applications will also be discussed. View Publication

Pluripotency of embryonic stem cells (ESCs) is defined by their ability to differentiate into three germ layers and derivative cell types and is established by an interactive network of proteins including OCT4 (also known as POU5F1; ref. ),NANOG (refs ,),SOX2 (ref. ) and their binding partners. The forkhead box O (FoxO) transcription factors are evolutionarily conserved regulators of longevity and stress response whose function is inhibited by AKT protein kinase. FoxO proteins are required for the maintenance of somatic and cancer stem cells; however,their function in ESCs is unknown. We show that FOXO1 is essential for the maintenance of human ESC pluripotency,and that an orthologue of FOXO1 (Foxo1) exerts a similar function in mouse ESCs. This function is probably mediated through direct control by FOXO1 of OCT4 and SOX2 gene expression through occupation and activation of their respective promoters. Finally,AKT is not the predominant regulator of FOXO1 in human ESCs. Together these results indicate that FOXO1 is a component of the circuitry of human ESC pluripotency. These findings have critical implications for stem cell biology,development,longevity and reprogramming,with potentially important ramifications for therapy. View Publication